/*顶部广告*/
.header{
    width:100%;
    height: 86px;
    background-color: black;
    position: relative;
}
.header img{
    height: 86px;
    text-align: center;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}
/* 黑色导航 */
.black-nav {
    background-color: #333;
    width: 100%;
    height: 40px;
    line-height: 40px;
    font-size: 12px;
}
.black-nav .wrap {
    width:1226px;
    margin: 0 auto;
    height: 40px;
}
.black-nav .wrap li {
    float: left;
    position: relative;
}
.black-nav .wrap li a {
    color: #b0b0b0;
}
.black-nav .wrap span{
    color:#424242;
    margin: 3.6px;
}
.black-nav .wrap .black-nav-left {
    float: left;
}
.black-nav .wrap .black-nav-right {
    float: right;
}
.download {
    width: 124px;
    height: 0;
    background: #fff;
    position: absolute;
    top: 40px;
    left: 50%;
    margin-left: -62px;
    overflow: hidden;
    box-shadow: #b0b0b0 0 1px 5px;
    text-align: center;
    font-size: 14px;
    line-height: 1px;
}
.download img {
    width: 90px;
    height: 90px;
    margin: 18px auto 12px;
    display: block;
}
.black-nav .wrap .black-nav-left li:hover>.download {
    height: 148px;
}